Down Pipe
 

I have a hole in my stock 87 turbo downpipe and am looking to replace. If I do so, I might as well improve and not just replace. It appears that most readily available down pipes out there are 3 inch. What was the stock size? Is there a big difference between different down pipes? If so, what should I look for ?

I believe I still need cats in my area. Although, there is not an emissions test as part of yaerly vehicle inspecton - they are talking about starting it in the near future.

For the moment, I was only looking at replacing the downpipe as it has a hole in it. However, if I can afford to change the hole system I will. Is that necessary, or will changing just the downpipe also give some HP gains ?

Pre August 1992 vehicles in the UK are allowed a higher limit of emissions. There for its very common to run without cat`s. This front down pipe Link is a very common replacement/upgrade, it removes the first cat and just connects to the front section of the second cat. Alternatively many owners replace the whole system with this Link which is the same as the Mongoose exhaust Link but at half the price.

http://i17.photobucket.com/albums/b5...iff/7M-GTE.jpg